应力波与缺陷相互作用的宏观微观数值模拟

Microscopic and macroscopic numerical simulation on interaction between stress wave and flaw

分别利用LS-DYNA3D有限元程序以及分子动力学方法,从宏观与微观两个层次模拟在动态拉伸载荷作用下含有预置缺陷的薄板中的塑性区形成与演化过程,以及随之而来的动态失效行为。计算结果表明,动态加载下塑性区的形成是应力波与缺陷相互作用以及应力波与应力波相互作用的结果。宏观尺度的LS-DYNA模拟与微观尺度的分子动力学模拟展现出相似的物理特征,即动态载荷下裂纹将萌生在缺陷边缘的前端,然后与缺陷边界连接,最终导致整体破坏。

The finite element program LS-DYNA3D and the molecular dynamic method were applied to investigate the plastic zone formation, evolution process and the consequent dynamic failure behaviors under the dynamic tensile loading in a metal sheet with a preset flaw at macroscopic and microscopic levels, respectively. The calculated results show that the formation of the plastic zone stems from the stress wave-flaw and stress wave-stress wave interactions. The macroscopic and microscopic simula- tions represent the similar physical characteristics： the crack initiates at the front of the flaw bounda- ry, then connects with the flaw and eventually leads to the global failure.